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Singlet Oxygen Reactions with Flavonoids. A Theoretical – Experimental Study

Authordc.contributor.authorMorales, Javier 
Authordc.contributor.authorGünther Sapunar, Germán es_CL
Authordc.contributor.authorZanocco Loyola, Antonio es_CL
Authordc.contributor.authorLemp Miranda, Else 
Cita de ítemdc.identifier.citationPLoS ONE 7(7): e40548. 2007en_US
General notedc.descriptionArtículo de publicación ISIen_US
Abstractdc.description.abstractDetection of singlet oxygen emission, lmax = 1270 nm, following laser excitation and steady-state methods were employed to measure the total reaction rate constant, kT, and the reactive reaction rate constant, kr, for the reaction between singlet oxygen and several flavonoids. Values of kT determined in deuterated water, ranging from 2.46107 M21s21 to 13.46107 M21s21, for rutin and morin, respectively, and the values measured for kr, ranging from 2.86105 M21s21 to 65.76105 M21s21 for kaempferol and morin, respectively, being epicatechin and catechin chemically unreactive. These results indicate that all the studied flavonoids are good quenchers of singlet oxygen and could be valuable antioxidants in systems under oxidative stress, in particular if a flavonoid-rich diet was previously consumed. Analysis of the dependence of rate constant values with molecular structure in terms of global descriptors and condensed Fukui functions, resulting from electronic structure calculations, supports the formation of a charge transfer exciplex in all studied reactions. The fraction of exciplex giving reaction products evolves through a hydroperoxide and/or an endoperoxide intermediate produced by singlet oxygen attack on the double bond of the ring C of the flavonoid.en_US
Type of licensedc.rightsAttribution-NonCommercial-NoDerivs 3.0 Chile*
Link to Licensedc.rights.uri*
Títulodc.titleSinglet Oxygen Reactions with Flavonoids. A Theoretical – Experimental Studyen_US
Document typedc.typeArtículo de revistaen_US

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